This invention relates to a stepping-motor-operated damper for opening and closing a baffle which is faced with a cold air intake of a refrigerator, and more particularly to a method of electrically detecting the position where the baffle is stopped.
A recent refrigerator has a freezing chamber and a refrigerating chamber. The refrigerating chamber is divided, for instance, into two parts, and the cold air in the freezing chamber is supplied into the two refrigerating chambers.
The supply of the cold air is controlled by operating, opening and closing, dampers which are provided in passageways connected between the freezing chamber and the two refrigerating chambers.
The refrigerator damper operates as follows: Two operating modes, namely, a fully opening mode and a fully closing mode, of a baffle driven by an AC synchronous motor are detected with a reed switch. In response to the operation modes thus detected, the baffle is operated to control the supply of the cold air thereby to control the temperature of the refrigerator.
On the other hand, Unexamined Japanese Utility Publication No's Sho. 58-87083 and Sho. 60-2271 have disclosed a technique that instead of the AC synchronous motor, a pulse motor, a typical example of which is a stepping motor, is employed.
In this case, the switch often becomes out of order at low temperatures, and in addition the freezing of the baffle cannot be detected in a short time. Hence, sometimes the refrigerator is unsatisfactory in operation.